Fire unit for furnaces



Aug. 8, 1933. F. c. GREENE FIRE UNIT FOR FURNACES 2 Sheets-Sheet l Filed Aug. 27, 1928 [lll/lill,

frank Green@ .BY @ag/ 66M a @m ATToRNEy,

Aug. 8, v E Q GREENE FIRE UNIT FOR FURNACES Filed Aug. 27, 1928 2 sheets-sheet 2 illllill l/O Y' c V.s

O ELAY THEMT/qf o o o Mo 701 Sf//rcf/ MAG/VET 46 POLE PIECE INVENTOR. yf/fz/ @Z105/ze BY A @my l f y Q ATTORNEY.

Patented Aug. 8, 1933 f FIRE UNIT FOR FURNACES Frank C. Greene, Milwaukee, Wis.

Application August 27, 1928. Serial No. 302,320

I0 Claims.

The present application relates, as indicated, t0 a re unit, and more particularly to units of such character which may be easily installed in an ordinary furnace and in which solid fuel will be gasiiied, the gas so generated to be burned in the usual combustion chamber of the furnace. The primary object of the invention is to devise a unit of the character described which shall be simple in construction, easily operated, and :relatively free from disorder. Further objects of the invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention, then, consists of the means hereinafter fully described and particulai-ly pointed out in the claims; the annexed drawings and the following description setting forth in detail certain mechanism embodying the invention, such disclosed means constituting, however, but one of various forms in which the principle of the invention may be used.

Figure l isa substantially central vertical section through a furnace having installed therein a unit built in accordance with the present invention; Fig. 2 is a diagrammatic showing of an electrical circuit connected in operative relation with the furnace.

In Figure l, the reference numeral 1l refers generally to the furnace, said furnace comprising a combustion chamber' 12 and ashpit or the like 13, the bottom wall of said furnace being formed with an aperture 14, providing communication between said combustion chamber and said ashpit.

The fire unit proper comprises a frame mounted upon wheels 16, and carrying an annular support member 17 on its upper surface. This support 17 carries on its inner surface a plurality of rolls 18 upon which is rotatably mounted the peripheral edge 19 of a substantially conical hearth member 2G. As will be clear, said member is mounted with its apex directed downwardly, said apex being received, in the embodiment shown, in an aperture 22 formed in the base of said frame 15. A substantially frustoconical nre-pot cover member 23 has a peripheral flange around its base, said iiange being secured to said support member 17, and said cover member cooperates with said hearth member to form an enclosed re pot as shown.

The nre-pot cover member 23 is open at its upper end, as at 24, and a plurality of links 25 have their lower ends pivoted to the upper open end 24 of said nre-pot cover member 23. At their upper ends, said links are pivoted to a iiared (Cl. 11G-45) flange 26 comprising the upper open end of a gas-oif-take tube 27. The links 25 thus form the support for said tube 27, and carry said tube with its lower end 28 slightly spaced from the bottom of the hearth member 20.

A bell 29 is formed in one side of said member 23 and rotatably receives one end 30 of a fuel delivery tube 31. Said end 30 extends slightly within the nre pot and has secured thereto or formed integrally therewith a cam pusher 32 for 65 a purpose laterV to be described.

At its opposite end, said tube 31 has keyed thereto a worm gear 33, and said gear meshes with a worm 34 formed on or carried by a spindle 35 of a motor 36 mounted on said frame 15. 70 Said Worm and gear are enclosed in a gear casing 37. A cradle 38 is secured to or formed integrally with the gear casing 37 and is adapted to vsupport a fuel container (not shown) into which is adapted to project the end 39 of said tube 31. As shown, the end 39 of said tube is cut away so that, as said tube rotates, the end 39 in the container will agitate the fuel therein and will cause said fuel to fall into said tube and be carried downwardly through such tube and into the nre pot. Adjacent the end 30 of said tube there is secured thereto a gear 40. Support 17 is formed with a journal 41 in which is mounted for rotation a stub shaft 42. A gear 43 is secured to one end of said stub shaft 42, and said gear meshes with the gear 40 on said tube 31. To the opposite end of the shaft 42 there is secured a bevel gear 44, which cooperates with a series of teeth 4.5 formed on the under side of said hearth member adjacent to the periphery thereof.

It will be seen that, as the motor 36 rotates the delivery tube 31, the gear 40 will drive the stub shaft 42, which, in turn will cause rotation of the hearth 20.

I have provided for automatic control of the unit as follows: Referring to Fig. 2, a suitable magnet 46 is diagrammatically illustrated, said magnet being mounted inthe frame 15 and the pole piece 47 therefor being mounted on an arm 48. This armis, in turn, connected to the gas off-take tube 27. A thermostat 49 is mounted on the cover member 23 vand is connected by wires 50 to a relay 51 which operates a motor switch, and by a wire 52 to said magnet 46.

It will be noted that the iiared end 26 of the tube 27 is normally located closely below the rim of the aperture 14, and closely above the upper end 24 of the fire-pot cover member 23. Thus it will be seen that, as the tube 27 is oscillated,

the links act to cause slight vertical movement of said tube, whereby said flared end 26 is brought into closer relation either with the rim of the aperture 14 or with the upper end 24 of the lire-pot cover member 23.

Assuming that the apparatus has stopped. rotating during a stand-by period, the combustion which proceeds during such period will gradually eat into the fuel present until the fuel bed becomes heated toward its periphery and causes the thermostat 49 located in the wall of the firepot to close an electrical circuit which energizes a relay 51 to close the motor circuit, whereby said motor will cause the rotation of the tube 31 and of the hearth member 20. At the same time, the magnet 46 is operated by the motor current to magnetize the pole piece 47 which attaches itself to the tube 3l and rotates therewith, causing the arm 48 attached thereto te rotate slightly. This swings the links 25, shown in Fig, 1, moving the tube 27 slightly in a circumferential direction and also upwardly, thus elevating the tube to increase the space 54 between the flare 26 and the upper end 24 of the cover member 23. Since the tube 27 does not rotate, the arm is held against further movement and the supply tube 31 may slide past the pole piece without further actuating the tube 27. When the motor stops due to cooling of the space around the thermostat, the magnet, which operates by means of the motor current, is de-energized and the pole piece 47 is released, whereupon the gas off-take tube 27, which is a heavy element, drops back and drags the links25 downward, returning the arm 48 to its normal position for stand-by of the apparatus. When the gas off-take tube is raised air immediately begins to flow into the Firebox through space 54,

, under the inlduence of the draft created in the furnace 11, and such air is drawn downwardly between the surface of the tube 27 and the incandescent portion 55 of the fuel wall to effect combustion of the fuel in said incandescent layer. The space 54 is so proportioned as to prevent admission to the iirepot of air in quantities sufficient to cause complete oxidation of said fuel. As a consequence, gases deficient in oxygen are generated in the firepot and are drawn upwardly through the gas-off-take tube 27 and into the combustion chamber 12 of the furnace 11. As such gases pass through the aperture 14, they are mixed with air entering through the space 56 between the rim of said aperture and the nare 26 of said tube 27. Since the gases are at a very high temperature, combustion thereof takes place immediately upon the mixture thereof with air. The reaction above described is set out much more fully in my co-pending application for Coal appliance, Serial No. 238,976, filed December 9, 1927, Patent No. 1,899,686. As the fuel is burned,the draft of air sweeping down over the incandescent wall entrains the particles of residual ash, and such particles are carried with said gases outwardly through the combustion chamber 12 and out of the stack. The swirling currents of air and gas adjacent the lower end 23 of the tube 27 may cause deposition of a certain amount of such ash, and a small pile thereof is shown at 57.

As the fuel is eaten a y cm the internal surface of the fuel wall, fro h fuel is pushed toward such surface by the cam pusher 32 of the tube 31. Since said tube 3l is rotating and since the hearth 20 is rotating and carrying with it the fuel wall, the effect of the pusher 32 is to form the fuel mass into a spiral ribbon, as will be readily understood. Shortly before the fuel reaches the incandescent surface of the fuel wall, it passes through a region of temperature such as to bring the fuel into a plastic condition. At a certain stage in this zone, the fuel becomes brittle, and consequently cracks are formed therein. Such cracks are continued into the incandescent surface of the fuel wall and there very materially increase the reactive surface of the fuel wall.

When the fuel bed has been built up by the fuel fed into the fire pot through the tube 31, the temperature in the neighborhood of the thermostat 49 drops, causing the device to open the motor circuit. The motor then stops, rotation of the tube 3l ceases and no more fuel is fed to the nre pot until that present has been slowly consumed and the incandescent region again approaches the outer periphery of the flrepot. The opening of the motor circuit also de-energizes the magnet 46 and permits the tube 27 to drop down and decrease the space 54 so that less air passes over the fuel during the stand-by period. As the incandescent surface of the fuel bed again approaches the thermostat, the motor circuit is again closed and fresh fuel, together with increased draft, are again supplied.

It will oe seen that I have devised a unit which may be readily used in connection with an ordinary furnace, said unit being mounted on wheels so that it may be entered directly into the ash door of a furnace. In lighting the unit, I prefer to draw the unit out of the ash pit 13, feed the same with a light fuel, such as sawdust, paper, or rag and light the fuel by means of a match dropped into the open end 24 or through a suitably provided igniting door in the re-pot-cover member 23. Afterthe light fuel begins to burn, the unit may be once more pushed back into the ash pit 13, and thereafter coal or other heavy fuel may be fed into the unit.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the stated by any of the following claims, or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention:-

1. A fire unit comprising a frame, a fire pot mounted on said frame and comprising a rotatable hearth and a fire-pot cover for said hearth, an open-ended tube mounted on said frame and having its lower end positioned in said fire pot iis adjacent the bottom thereof, and means mounted on said frame for feeding fuel to said lire pot.

2. A re unit comprising a wheeled frame, a lire pot mounted on said frame and comprising a rotatable hearth and a re-pot cover for said hearth, an open-ended tube mounted on said frame and having its lower end positioned in said nre pot adjacent the bottom thereof, and means mounted on said frame for feeding fuel to said fire pot.

3. A furnace having a combustion chamber, a pit therebelow, and an aperture connecting said chamber and pit, a fire unit comprising a frame, a gas generator mounted on said frame and positioned in said pit in registry With said aperture, means mounted on said frame for feeding fuel to said generator and a gas off-take tube oscillatably mounted in said aperture.

4. A furnace having a combustion chamber, a pit therebelow, and an aperture connecting said chamber and pit, a fire unit comprising a portable frame adapted to be moved into and out of said pit, a gas generator mounted on said frame and positioned in registry with said aperture, means mounted on said frame for feeding fuel to said generator and a gas orf-take tube oscillatably mounted in said aperture.

5. A furnace having a combustion chamber, a pit therebelow, and an aperture providing communication between said chamber and said pit, a nre unit comprising a frame adapted to be positioned in said pit, a gas generator having an open top adapted to register with said aperture and comprising a hearth rotatably mounted on said frame, a nre-pot cover for said hearth, and a gas-oiF-talre tube mounted on said iire-pot cover and extending within the saine, a supply tube having one end extending through an aperture in said cover adapted to deliver fuel to said generator, means mounted on said frame for rotatingr said supply tube, and means including said tube for rotating said hearth.

6. A furnace having a combustion chamber, a pit therebelow, and an aperture providing communication between said chamber and said pit, a iire unit comprising a frame adapted to be positioned in said pit, a gas generator having an open top adapted to register with said aperture and comprising a hearth rotatably mounted on said frame, a lire-pot cover for said hearth, and a gas-offtal;e tube mounted on said nre-pot cover and extending within the a supply tube having one end extending through an aperture in said re-pot cover and adapted to deliver fuel to said generator, means mounted on said frame for rotating said supply tube, means including said tube for rotating said hearth, and means including said tube for oscillating said take-oil tube.

A furnace having acombustion chamber, a pit therebelow, and an aperture providing communication between chamber and said pit, a rire unit ccprising a frame adapted to be positioned in pit, a gas generator having an open top adapted to register' to said aperture and comprising a hearth rotatably mounted on said a iire-pot cover for said hearth, and a gas-oftale tube oscillatably mounted on said rlre-pct cover and extending within the same, said tube being movable substantially into contact with the rim of said furnace aperture at one extre; Le and substantially into contact with the top of said iire--pot cover at the other extreme, a supply tube having one end extending through .an aperture in said iire-pot cover and adapted to deliver fuel to said generator, means mounted on said frame for rotating said supply tube, means including said tube for rotating said hearth, and means including said tube for oscillating said off-take tube.

3. A furnace having a combustion chamber, a pit tlierebelow, and an aperture providing com-- munication between said chamber and said pit, a re unit comprising a frame adapted to be positioned in said pit, a gas generator having an open top adapted to register with said aperture and comprising a hearth rotatably mounted on said frame, a re-pot cover for said hearth, and

,a gas-olf-take tube mounted on said fire-pot cover and extending within the same, a supply tube having one end extending through an aperture in said re-pot cover and adapted to deliver fuel to said generator, said supply tube being formed with a cam pusher on its delivery end, means mounted on said frame for rotating said supply tube and means including said tube for rotating said hearth.

9. A furnace having a combustion chamber, a pit therebelow, and an aperture providing communication between said chamber and said pit, a fire unit comprising a frame adapted to be positioned in said pit, a gas generator having an open top adapted to register with said aperture and comprising a hearth rotatably mounted on said frame, a nre pot cover for said hearth, and a gas-off-take tube mounted on said firepot cover and extending within the same, a supply tube having one end extending through an aperture in said fire-pot cover and adapted to deliver fuel to said generator, a motor mounted on said frame, a worm gear keyed to said supply tube, a Worm secured to the spindle of said motor and meshing with said' gear and means including said tube for rotating said hearth.

1Q. A furnace having a combustion chamber, a pit therebelow, and an aperture providing communication between said chamber and said pit, a nre unit comprising a frame adapted to be positioned in said pit, a gas generator having an open top adapted to register with said aperture and comprising a hearth rotatably mounted on said frame, a fire-pot cover for said hearth, and a gaseoiT-take tube oscillatably mounted on said fire-pot cover and extending Within the same, said tube being movable substantially into contact with the rimof said furnace aperture at one extreme and substantially into Contact with the top of said fire-pot cover at the other extreme, a supply tube having one end extending through an aperture in said fire-pot cover and adapted to deliver fuel to said generator, said supply vtube being formed with a cam pusher on its delivery end, a motor mounted on said frame, a worm gear keyed to said supply tube,

a worm secured to the spindle of said motor and f meshing with said gear, a spur gear keyed to said supply tube, a stub shaft journalled in` said' 'said stub shaft and meshing with said hearth teeth, and electro-magnetic means cooperable with said supply tube for oscillating said olf-take tube.

FRANK C. GREENE. 

